Stoker furnace



sept. 22, 1925.

J. S. SKELLY STOKER FURNACE Filed Jan.A 13 1920 J. S. SKELLY STOKER FURNAC Sepf. 22, 1925.

'Filed Jan. 13. 1920 2 Shee'S-She 2 Patented Sept. 22, 1925.

UNITED sTATEs PATENT OFFICE.

JOHN S. SKELLY, O'F MONONGAHELA, PENNSYLVANIA, SSIGNOR TO COMBUSTION ENGINEERIG CORPORATION, OF NEW YORK, N. Y., A CORPORATION OE 'NEW YORK.

sToKEza FUR'NACE.

Application flled January 13, 1920. Serial No. 351,187.

To all 'witam z't may 00noern.'

Be it known that I, JOHN S. SKELLY, a citizen of the United States, residing at Monongahela, county of Washington, State of Pennsylvania, have linvented a certain new and useful Improvement'in Stoker Fur'- naces, of which the following is a full, clear, and e'xact description. 4

My invention relates to stoker 'furnaces andhas for its object to provide a front underfeed stoker inwhich fuel is fed to the grate with a substantially uniform thickness at all points; it further has for its object i to provide a suitable pusher mechanism acsists in the use of internal cams for tuated by a shaft rotating slowlyin one direction and free from crank arms or movable links.

One feature of my invention consists in the use of an inclined grate and a retort extending practically or substantially the full I width of the grate, and means for underfeeding fuel from thel front directly. through said retort to the grate at all points along the front edge thereof; another feature con-` reciprocating the pushers' The following is a description of an emi bodiment of my invention; reference being had to the accompanying drawings, in which,

Fig. on the line 1-1, Fig. 2,;

Fig. 2 shows a Vertical section on the line 2 2, Fig. 1, part of the side wall being removed;

Fig. 3 shows an enlarged detail of the.

means for reciprocating the pusher and grate bars, while i Fig. t shows a modification'of the same; Figs. 5 and 6 are sectional details of grate bars of the stoker.

Fig. 7 shows on a reduced scale, a fragmcntary plan view of portions of the two sets of grate bars and their supports and means for reciprocating alternate bars.

Referring more particularly to the drawings, 1 is the furnace setting carrying the stoker mechanism. 2 is a hopper for fuel discharging at its lower end into a. passage 3, from whence it is forced byv reciprocating pushers 4, 4 toward a set of inclined grate bars 5, 5, constituting the upper section of the grate, the upper ends of which are supported by the lower wall of the passag'e 3,

f while the lower ends are supported by a i' wall 6.

'l shows a horizontal sectional view Below the section containing the grate bars 5, 5' is another set of grate bars 7, 7', constituting' the lower section of the grate, which are preferably not inclined to the same extent as the bars 5, 5'. The upper ends of the bars 7, 7' are supported by a wall 8, while their lower ends are supported by a wall 9. In each of the two Sections the alternate grate bars 5 and 7 are movable, the intermediate bars 5' and 7' being stationary after the manner shown in patent to W. R. W'ood, No. 818,010 granted April 17, 1906. In order to move the movable bars, they are provided on their under sides with recesses 10 and 1l` in which fit fianges upon rocker bars 12 and 13 respectively. These rocker bars extend half-way across each grate section, as shown, so that they can be independently actuated. To theouter ends of Meshing with eall gear 20 'is a gear 21,

these gears'2l being upon'shafts 22 upon each of which shafts are secured two radially projectinginembers 23 each provided with an anti-friction roller 24. These radially projecting' members 23 rotate within. frames 25 each frame 'having'abutments 26 and 27 facing in opposite directions. These abutrnents are on different' sides of the vertical plane passing through the axis of the shafts 22. i

The gears 21 are drive-n by any suitable means such asgears '28 meshing therewith so as to cause the shafts 22 and projections 23 to revolve slowly in a clockwise direction. As these members arerevolved the anti-friction rollers 24v engage the abutments 27 to move the frames and pushers 4: connected,therewith to'the right (Fig. 2) feeding'coal from the discharge of the hopper toward the stoker grate. A further movement of the shafts 22 causes the antifriction rollers 23 to engage tlre abutmen'ts 20 causing th pushers 4 to move to 'the left 1 so as-to be in ;z position to force forward more coal upon its next forward stroke. At

- the movable bars 1n the upper .and lower section an air duct 29 30' "controls th1s` air.

'ing upon 'lar barsl 7,

grate Sections. to reciprocate, the movablebars in the two sections moving in' opposite directions.

The opening 3 extends the full width of the grate made up of the bars 5, 5' and the pushers 4, .4 extendl the full width of that opening except for a' narrow supporting wall 4' which is located between adjacent sides of the pushers when necessary, dependthe width of the pushers and their number. The forward wall of the hopper 2 is provided with an' opening through which the pushers 4: extend and substantially fill thepsame.. 'The mouth of the hopper is of similar width, so that the pushers 4, 4 feed fuel to all parts of the upper end of the grate. Byvthese full width pushers the fuel'v is underfed with ansubstantially 'uniform' thickness to all points along the -upper end of the upper section. The portion 3' of the opening, adjacent to the 4upper ends of the bars 5, .5', constitutes a retortfor coal to be burned upon the grate.

In order to supply air to the upper grate' is provided which supplies air to the Chamber 80, formed beneath the upperv ends of the bars 5 by the wall 31.

This causes air to pass through the inlet.``

orts 52 of the tubular bars 5, 5' so as to-be. ldischarged into the chamber 82 between the walls 6 and 31 through the outlet ports 5? located adjacent to the lower. ends of. the bars. 30,' is a damperfor controlling this air. An air duet 302 Supplies air to thev cham. r between the walls 6 and 8 for the inlet ports 7z located at the upper ,ends of the bars 7, 7'. The air is discharged through `outlet ports 7 a located at the 'lower ends of the bars7, 7' into the chamb'er 33 formed by the walls 8 and 9, from whence it passes upward between the bars-7, 7' of the lower section to the superimposed fuel.. A darnper The Vair passing 5, 5' passes upwardhe'-` through the bars tween those bars 'to the superlmposed fuel l while the air which passes through the tubu- 7' passes upward .between those bars. In this way the air to the two rate Sections can be independently controlle.

The result of the operation ofl the appa-V ratusabove described is that 'coal is under- 1 fed slowly by the internal camoperated pushers from the hopperv directly through the. retort to the upper fgrate'section so-.asz-

to be of uniform thickness throughout its width and' caused'to move down the grate by the moving'bars thereof to the lower section,V where similar movements result in further progressive movement of the fuel at any desired slowerrate. Primary com bastion takes place upon the grate bars of the rocker the upper section and the air f'palssing through those grate bars is heated thereby. The complete combustion takes place on the lower section where by retarding the. movement the partially .burned fuel can be con- 'solidated so as 'to prevent thin spots,

25' connected to each pusher,-eachframe ac tuated by a projection 28. There are also 14 and 15, holes in the lever arm` the such regulation being 0btwo independent. shafts 22 carrying the prow jections for the two separate pushers and sponding rocker `bars can be driven at different speeds if desired. w

34 is an ash grate mounted'upon a shaft 35 which is actuated through aworm gear 36by a worm 37. y The movable 'stationary bars 5' and the stationary bars 7' are inline with movable bars 5. 'Thisar-` rang'ement assists in maintaining'V an even flow of fuel over the lower grate section;`

In the modification shown in Fig. {lthe frame 25' barsz.'12 and.-=-.13 aredividedgat theircenters to form. two independent' sectionsso that the pushers and.the correbarsj7 are in line with the v connected to the l-pusher 42 instead of having two internal abutments is provided with a series of such abutments 26' and 27' om the two opposing faces and the shaftisprovided with a plurality of radiali projections 23' constitutin a segment of the gear wheel, having as distinguished from Fig. 3; The resulting motionifis the same, except that in the construction' ofl Fig. 4 greater movement is member of the same diamete'r. a

As will .beevident to. those skilled in the art, my invention permits fictions 'without departing 'from 'the spirit thereof or th e s'cope' of the appended 'claimsf What 'I claim i's:

1. An underfeed 'stoker furnace having, in combination, an inclined grate, aretort at' the upper end of the grate extending substantially .the full width of the grate 'and having anopening' in its forward side 'substantially of the width of the grate, a. 'narrow partition intermediate the ends of the retort having its rear end substantially in front of the forward end of the grate, a hopper connected with the opening in lthe retort, and closely adjacent reciprocating of various modiafp urality ofteeth the single-tooth ofv obtained for a rotatin'g pushers arranged at o posite sides of the partition and each of su stantially the width of the .space between said Partition and the adjacent outer side wall of said opening.

2. An underfeed stoker having, 1n combination, a fuel feeding grate comprising ining said opening in the forward wall of the in combination, a grate,

hopper and composed of a lurality lof closely adjacent Sections, andP means for reciprocating said Sections independentlyl of each other.

3. An underfeed stoker furnace having,

a fuel retort extending across the front end of' said grate, a hopper having its lower end in communication with the forward end of said retort, fuel pushers mount'ed to slidel in an, opening in the lower end of the front-wall of the hopper for feeding`` fuel into said retort, said pushers closing said opening and being g'uided by the walls thereof, and means for i actuating said pushers comprising 'a plurality of frames carrying each pusher and located in front of the forward end of said opening and outside of the furnace, and rotating members extending through the frames, each of said frames having suitably arranged abutments, and each of said rotaitfjfi J mg members having suitable pro-]ect1ngf means adapted to engage said abutinents'v alterna'tely so as to reciprocate said frame I and pusher.

i JOHN S. SKELLY. 

